Cationic antimicrobial peptides (CAPs) occur naturally as innate immunity agents in a wide spectrum of living organisms including humans, and have become increasingly recognized as templates for prospective antibiotic agents.
Certain cationic antimicrobial peptides, including KKKKKKAAFAAWAAFAA-NH2 (SEQ ID NO:3), are known from CA 2,451,310, where such peptides are described as showing antimicrobial activity against microorganisms including Gram-negative and Gram-positive bacteria.
Yin et al. (JBC, 287:7738-7745, 2012) explain that cationic antimicrobial peptides offer an alternative to conventional antibiotics, as they physically disrupt bacterial membranes, causing cell death. It was shown that peptides designed with high hydrophobicity display strong self-association that is minimized by distribution of positive charges at both peptide termini and it was concluded that balancing peptide hydrophobicity and charge distribution promotes efficient antimicrobial activity.
Bacterial biofilms are surface-attached microbial communities enclosed in extracellular polymeric substance (EPS). Sixty percent of all infectious diseases are caused by biofilms and organisms causing such diseases are up to 4000 times more resistant than the same organism in a free-floating or ‘planktonic’ state.
There remains a need to identify novel methods of penetrating bacterial biofilms in order to specifically treat or prevent various infectious diseases.